为什么我收到EOFError

问题描述

我正在使用 tkinter和urllib 制作此程序，该程序应该像一个下载管理器。在我几乎完成该程序后，我意识到我没有为下载定义取消按钮。在深入研究之后，我发现了关于 multiprocessing 的信息（在我刚使用线程之前），显然，与并行运行线程的线程相比，它是比线程更好的模块，并且它还具有终止功能。但是，无论我做什么，我似乎都无法理解此模块。它比线程复杂得多，而且我总是会遇到荒谬的错误。在我的程序中，我不断收到此错误：

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\tkinter\__init__.py",line 1883,in __call__
    return self.func(*args)
  File "C:/Users/Family/PycharmProjects/8-bit Downloader/test.py",line 258,in start_download
Process(target=download_files,File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\process.py",line 121,in start
    self._popen = self._Popen(self)
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\context.py",line 224,in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\context.py",line 327,in _Popen
    return Popen(process_obj)
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\popen_spawn_win32.py",line 93,in __init__
reduction.dump(process_obj,to_child)
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\reduction.py",line 60,in dump
    ForkingPickler(file,protocol).dump(obj)
TypeError: cannot pickle '_tkinter.tkapp' object
Traceback (most recent call last):
  File "<string>",line 1,in <module>
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\spawn.py",line 116,in spawn_main
    exitcode = _main(fd,parent_sentinel)
  File "C:\Users\Family\AppData\Local\Programs\Python\Python38-32\lib\multiprocessing\spawn.py",line 126,in _main
    self = reduction.pickle.load(from_parent)
EOFError: Ran out of input

我完全不知道是什么导致了此错误，以及如何解决该错误。 start_download（）函数似乎有问题。我的代码（我知道它有一些缺陷，我可以使其更整洁，我只是想在完成基础知识之后再做，如果您认为某些部分不相关，请通知我。）

import os
import sqlite3
import time
import urllib.request
from multiprocessing import Process
from pathlib import Path
from tkinter import *
from tkinter import filedialog
from tkinter import font
from tkinter import messagebox
from tkinter import ttk
import numpy as np
import requests
import win10toast
from PIL import Image,ImageTk

files_downloading,times_clicked,dir_files = 0,{}
info_window,customize = None,None


# The problem I believe is with the two functions below and the start function some of the code is related to the downloads tab
# which is irrelevant and some other were just functions that were unrelated so if you see a button without a function that
# exists or it is 'None' it is just deleted for the purpose of this question and also ignore the image variables!

def get_info(path,new_fullname,url_entry):
    global times_clicked
    lbl_await.pack_forget()
    prg_br.pack_forget()
    file_size = int(requests.head(str(url_entry.get()),headers={'accept-encoding': ''}).headers['Content-Length']) / 1000000
    print(file_size)
    file_dir = Path(str(path).replace(" \ ".strip(),"/") + "/" + new_fullname)
    size_eachsec = np.array([0.0,])
    my_scrollbar.pack(side=RIGHT,fill=Y)
    lbl_fr = ttk.LabelFrame(second_frame,text=new_fullname,padding=5)
    if len(new_fullname) > 20:
        lbl_fr.config(text=new_fullname[:21] + "...")
    download_prg = ttk.Progressbar(lbl_fr,orient=HORIZONTAL,length=365,mode='determinate',cursor="wait")
    lbl_speed = Label(lbl_fr,text=None)
    lbl_crnt_size = Label(lbl_fr,text=None)
    lbl_file_size = Label(lbl_fr,text=f"File size: {round(file_size,3)} MB")
    lbl_percent = Label(lbl_fr,text="0 %")
    lbl_cancel_btn = ttk.Button(lbl_fr,image=cancel_btn_icon)
    lbl_see_more = Label(second_frame,text="See more",fg="grey",font=("Arial",10))
    download_prg.grid(row=0,column=0,columnspan=2)
    lbl_speed.grid(row=0,column=2,padx=5)
    lbl_crnt_size.grid(row=1,column=1)
    lbl_file_size.grid(row=1,column=0)
    lbl_percent.grid(row=1,column=2)
    lbl_cancel_btn.grid(row=0,column=3,rowspan=2)
    lbl_fr.grid(row=times_clicked,padx=5,pady=5)
    lbl_see_more.grid(row=times_clicked,column=1,padx=3)
    times_clicked += 1
    start_time = time.time()
    while True:
        if file_dir.exists():
            time.sleep(0.5)
            crnt_size = file_dir.stat().st_size / 1000000
            size_eachsec = np.append(size_eachsec,crnt_size)
            percent = (crnt_size / file_size) * 100
            crnt_speed = size_eachsec[1] - size_eachsec[0]
            size_eachsec = np.delete(size_eachsec,0)
            lbl_speed.config(text=f"{round(crnt_speed,2)} MB/s")
            lbl_crnt_size.config(text=f"Downloaded: {round(crnt_size,3)} MB")
            lbl_percent.config(text=f"{round(percent,2)} %")
            download_prg["value"] = percent
            # print( f"Current Size: {crnt_size},Current speed: {crnt_speed},File size: {file_size},# Percentage: {percent}% " f",Progress bar: {download_prg['value']}%")
            if crnt_size == file_size:
                break
    end_time = time.time()
    time_elapsed = end_time - start_time
    print(f"Start time: {start_time},End time: {end_time},Time took: {time_elapsed}")
    download_prg.config(cursor="arrow")
    lbl_speed.config(text="Completed!")

    def show_info(event):
        global info_window
        if info_window is not None and info_window.winfo_exists():
            info_window.focus_set()
            lbl_see_more.config(fg="purple")
        else:
            lbl_see_more.config(fg="purple")
            info_window = Toplevel()
            info_window.resizable(0,0)
            lbl_time_took = Label(info_window,text=f"Time elapsed: {round(time_elapsed,2)}")
            lbl_avg_speed = Label(info_window,text=f"Average speed: {round(file_size / time_elapsed,3)} MB/s")
            lbl_time_took.pack(pady=20)
            lbl_avg_speed.pack(pady=20)

    lbl_see_more.bind("<Button-1>",show_info)
    new_font = font.Font(lbl_see_more,lbl_see_more.cget("font"))
    new_font.configure(size=10,underline=True)
    lbl_see_more.config(font=new_font,fg="blue",cursor="hand2")
    print("Download successful! ")


def download_files(status_bar,url_entry,output_entry,name_entry,format_entry,num,chum,var):
    global files_downloading
    files_downloading += 1
    status_bar.config(text=f"Downloading {files_downloading} file(s)...")
    url = str(url_entry.get())

    if num.get() == 1:
        name = url.split("/")[-1].split(".")[0]
    else:
        name = str(name_entry.get())

    formatname = str(format_entry.get())
    if var.get() == 1:
        operator = str(url_entry.get())
        formatname = '.' + operator[-3] + operator[-2] + operator[-1]
    else:
        pass

    static_fullname = str(name) + formatname
    new_fullname = static_fullname
    path = (str(output_entry.get()) + "/").replace(" \ ".strip(),"/")
    if chum.get() == 1:
        conn = sqlite3.connect("DEF_PATH.db")
        c = conn.cursor()
        c.execute("SELECT * FROM DIRECTORY_LIST WHERE SELECTED_DEF = 1")
        crnt_default_path = c.fetchall()
        # print(crnt_default_path)
        path = str(crnt_default_path[0][0] + "/").replace(" \ ".strip(),"/")
        conn.commit()
        conn.close()
    else:
        pass

    if path + static_fullname not in dir_files.keys():
        dir_files[path + static_fullname] = 0

    all_files_dir = os.listdir(path)
    # if fullname in all_files_dir:
    while new_fullname in all_files_dir:
        dir_files[path + static_fullname] += 1
        if num.get() == 1:
            name = url.split("/")[-1].split(".")[0] + f" ({dir_files.get(path + static_fullname)})"
        else:
            name = str(name_entry.get()) + f" ({dir_files.get(path + static_fullname)})"
        new_fullname = name + formatname
    else:
        pass
    print(dir_files)

    Process(target=get_info,args=(path,url_entry)).start()
    urllib.request.urlretrieve(url,path + new_fullname)
    if len(new_fullname) > 20:
        toast.show_toast(title="8-bit Downloader",msg=f"{new_fullname[:21] + '...'} was successfully downloaded. to '{path}'",duration=6,threaded=True)
    else:
        toast.show_toast(title="8-bit Downloader",msg=f"{new_fullname} was successfully downloaded. to '{path}'",threaded=True)
    files_downloading -= 1
    status_bar.config(text=f"Downloading {files_downloading} file(s)...")
    if files_downloading == 0:
        status_bar.config(text="Download(s) successful!")


if __name__ == '__main__':
    root = Tk()
    tabs = ttk.Notebook()
    # the top menu
    num = IntVar()
    chum = IntVar()
    var = IntVar()
    toast = win10toast.ToastNotifier()
    
    def start_download():
        Process(target=download_files,args=(status_bar,var),daemon=True).start()


    # the status bar
    status_bar = Label(main_window,text="Awaiting download...",bd=1,relief=SUNKEN,anchor=W)
    status_bar.pack(side=BOTTOM,fill=X)

    # the download frame
    body_frame = Frame(main_window,bg="light blue")
    download_button = ttk.Button(body_frame,text="Download! ",command=start_download,padding=40,style='my.TButton')
    download_button_tip = CreateToolTip(download_button,"Initiates the downloading process. ")
    download_button.pack(side=LEFT,pady=5,padx=5)
    body_frame.pack(side=LEFT,fill=Y)


    def clear_entry(entryname,variable=None):
        if variable is not None:
            variable.set(0)
        entryname.config(state=NORMAL)
        entryname.delete(0,END)
        if entryname is format_entry:
            entryname.insert(0,'.')


    # the main interaction menu
    inter_frame = Frame(main_window)
    trash_icon = ImageTk.PhotoImage(Image.open("icons/Asset 6.png"))
    settings_icon = ImageTk.PhotoImage(Image.open("icons/Settings-icon.png"))
    add_icon = ImageTk.PhotoImage(Image.open("icons/Plus-icon-8.png"))
    minus_icon = ImageTk.PhotoImage(Image.open("icons/Minus-icon-8.png"))
    change_path_icon = ImageTk.PhotoImage(Image.open("icons/Change-icon-8.png"))
    url_entry = ttk.Entry(inter_frame,width=30)
    label = ttk.Label(inter_frame,text="Enter the image URL: ")
    clr_url = ttk.Button(inter_frame,image=trash_icon,command=lambda: clear_entry(url_entry))
    file_format = ttk.Label(inter_frame,text="Choose your file format: ")
    format_entry = ttk.Entry(inter_frame,width=30)
    clr_format = ttk.Button(inter_frame,command=lambda: clear_entry(format_entry,var))
    file_name = ttk.Label(inter_frame,text="File's name: ")
    name_entry = ttk.Entry(inter_frame,width=30)
    clr_name = ttk.Button(inter_frame,command=lambda: clear_entry(name_entry,num))
    check_name_manual = ttk.Radiobutton(inter_frame,text="Enter name manually",variable=num,value=0,command=lambda: name_entry.config(state=NORMAL))
    check_name_auto = ttk.Radiobutton(inter_frame,text="Download with default name",value=1,command=lambda: name_entry.config(state=DISABLED))
    check_format_manual = ttk.Radiobutton(inter_frame,text="Enter format manually",variable=var,command=lambda: format_entry.config(state=NORMAL))
    check_format_auto = ttk.Radiobutton(inter_frame,text="Download with default format",command=lambda: format_entry.config(state=DISABLED))
    output_path = ttk.Label(inter_frame,text="Choose output path: ")
    output_entry = ttk.Entry(inter_frame,width=30)


    def set_path():
        directory = filedialog.askdirectory(initialdir="/Downloads",title="Choose path")
        if directory:
            output_entry.delete(0,END)
            output_entry.insert(0,directory)


    select_path_btn = ttk.Button(inter_frame,width=3,text="...",command=set_path)
    select_path_btn_tip = CreateToolTip(select_path_btn,"Pops up a filedialog to change directory. ")


    default_path_btn = ttk.Button(inter_frame,image=settings_icon,command=None)
    check_default_manual = ttk.Radiobutton(inter_frame,text="Enter path manually",variable=chum,command=lambda: output_entry.config(state=NORMAL))
    check_default_auto = ttk.Radiobutton(inter_frame,text="Download to default path",command=lambda: output_entry.config(state=DISABLED))
    file_name.grid(row=0,pady=(15,10))
    name_entry.grid(row=0,10))
    clr_name.grid(row=0,pady=(5,0))
    check_name_manual.grid(row=1,padx=(10,0))
    check_name_auto.grid(row=1,0))
    label.grid(row=2,pady=10,0))
    url_entry.grid(row=2,0))
    clr_url.grid(row=2,column=2)
    file_format.grid(row=3,0))
    format_entry.grid(row=3,0))
    format_entry.insert(0,'.')
    clr_format.grid(row=3,column=2)
    check_format_manual.grid(row=4,0))
    check_format_auto.grid(row=4,0))
    output_path.grid(row=5,0))
    output_entry.grid(row=5,5))
    select_path_btn.grid(row=5,column=2)
    check_default_manual.grid(row=6,pady=(0,10),0))
    check_default_auto.grid(row=6,0))
    default_path_btn.grid(row=6,5))
    inter_frame.pack(expand=1)
    main_window.pack(fill="both",expand=1)
    # The Downloads tab (this part is irrelevant so I wouldn't bother checking this part out just put it there in case)
    lbl_await = ttk.Label(download_fr,text="Awaiting Download...",font=("Helvetica",24))
    prg_br = ttk.Progressbar(download_fr,length=250,mode='indeterminate')
    my_canvas = Canvas(download_fr)
    my_scrollbar = ttk.Scrollbar(download_fr,orient=VERTICAL,command=my_canvas.yview)
    my_canvas.configure(yscrollcommand=my_scrollbar.set)
    lbl_await.pack(pady=(85,8))
    prg_br.pack()
    prg_br.start(6)
    my_canvas.pack(side=LEFT,fill=BOTH,expand=1)
    download_fr.pack(fill="both",expand=1)
    second_frame = Frame(my_canvas)
    # Add that new frame to a window in the canvas
    my_canvas.create_window(0,window=second_frame,anchor='nw')
    # update canvas scrollregion whenever the size of second_frame is changed
    second_frame.bind('<Configure>',lambda e: my_canvas.configure(scrollregion=my_canvas.bbox('all')))
    tabs.pack(fill="both")
    tabs.add(main_window,text="Main Window")
    tabs.add(download_fr,text="Downloads")
    root.mainloop()

# the end!

解决方法

我认为您的主要问题是：

TypeError: cannot pickle '_tkinter.tkapp' object

您似乎正在尝试在进程之间传递Tk对象。我怀疑这样是否行得通。